The Japanese government has described the Southern Kuril islands - known in Japan as the Northern Territories - as the area "illegally occupied" by Russia in its Diplomatic Bluebook for the first time since 2003, media reported on Friday.

The Southern Kurils are also described as an "inherent part" of Japan for the first time since 2011, the Kyodo news agency reported. The Diplomatic Bluebook was presented by the Foreign Ministry to the government on Friday.

The move follows the Russian decision on refusing to negotiate a peace treaty with Japan, halting visa-free travel for Japanese citizens to the Southern Kuril Islands, and withdrawing from dialogue with Japan on establishing joint economic activities on the archipelago.

The Russian steps were made in response to the Japanese government's decision to join the sanctions against Moscow over its military operation in Ukraine.

Russia launched its military operation in Ukraine on February 24 to support the people's republics of Donetsk and Lugansk.

The Western countries have strongly condemned the operation calling it an "invasion" and imposed sanctions on Russia.

Tokyo seeks to damage Russia’s interests

On March 23, Russian Foreign Ministry Spokesperson Maria Zakharova pointed out that Russia "had no plans to continue peace treaty talks with Japan."

"It’s obvious because there is no way of discussing the signing of a basic document for bilateral relations with a country that has taken an openly unfriendly position," she considered.

According to Zakharova, Tokyo seeks to damage Russia’s interests. "Given the current situation and the Japanese leadership’s approach, it is impossible to talk about developing such documents," the Russian diplomat affirmed.

Sovereignty of islands cannot be challenged

It is noteworthy that the Japanese authorities have been refraining from using the term "occupation" when tackling the Kuril Islands issue until recently, following the war in Ukraine, when claims of these islands being under the Japanese sovereignty suddenly resurfaced. 

Russia and Japan have held talks over the World War II peace treaty and its implementation.

According to TASS, "After the war, the entire archipelago became a part of the Soviet Union, but Japan challenges the sovereignty of the islands of Iturup, Kunashir, Shikotan and a group of smaller uninhabited islands."

On the other hand, Russia has repeatedly affirmed that the sovereignty of these islands cannot be challenged, as it is protected by international documents.

Japanese-US alliance unprecedentedly strengthened

Japan has for the first time described the situation in the world as an interstate competition between the United States and China, media reported, citing the Diplomatic Bluebook, which was presented by the Japanese Foreign Ministry to the government on Friday

According to the Diplomatic Bluebook, the world has shifted from the US leadership, which ensured "peace and prosperity," to the US-Chinese competition, the Kyodo news agency reported.

The document said that some developing countries had boosted their presence across the world.

The Diplomatic Bluebook added that the Japanese-US alliance had been unprecedentedly strengthened.

Japan's Diplomatic Bluebook is an annual report on the country's foreign policy and international diplomacy published by the Ministry of Foreign.